while ( <MYFILE> ) {
   chomp;
   (my $txnid,my $date,my $custid,my $amount, my $productc, my $subc, my $city, my $state, my $mode) = split(",");
   my $key_to_reduce = join ".", "$subc", "$state";
   print "$key_to_reduce\t$amount\n";
}